JPH01227057A - Fractionation/measuring apparatus for polymer - Google Patents

Abstract

PURPOSE:To facilitate the maintenance of an apparatus, by performing a temperature control of a valve unit for altering passages, a molecule composition fractionation unit and a molecule size fractionation unit with respective independent automatic temperature controllers. CONSTITUTION:Heating containers of a passage altering valve unit A having an internal reference liquid injection mechanism which includes a sample polymer solution injection port, a sample polymer solution determination loop, a liquid determination loop and a liquid injection valve and a valve for altering system passages, a molecule composition fractionation unit B and a molecule size discrimination unit C are connected to automatic temperature controllers Aa, Ba and Ca respectively and set for a temperature enough to guarantee a free passage of a polymer solution independently. The control of the automatic temperature controllers Aa, Ba and Ca and valves within the unit A is performed with a system controller Ab. This accomplishes an independent temperature control for the units A, B and C thereby facilitating the maintenance of the apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION CI) Technical Field of the Invention The present invention relates to an apparatus for analyzing the correlation between the chemical structure or molecular structure of a polymer and its molecular weight in a short time.

Generally, a polymer is a mixture that is heterogeneous in any or all of its molecular species, such as molecular weight, chemical composition, and molecular structure. The quality of the polymer is then generally determined by these molecular species. Therefore, obtaining accurate distribution information regarding these molecular species is essential for research on improving the quality of polymers.

gel permeation chromatography (CGPC),
Fractional precipitation or dissolution methods and other polymer fractionation methods are means for this purpose. However, these fractionation methods only give information about one of the above molecular species. If the interrelationships between two or more molecular species are known, more advanced molecular design will become possible, and for this purpose it is conceivable to combine two or more types of separation means. However, in this case, two or more different fractionation methods are carried out two-dimensionally, i.e., one fractionation method is first used to classify a certain molecular species, and then a different fractionation method is applied to each of the resulting classifications. This requires a huge amount of manpower and time (generally, it takes more than -weeks).

There is a column method, which falls within the category of prior art fractional dissolution methods, and has been proposed as a method for determining the methyl branch distribution (composition distribution or, in this case, crystallinity distribution) in polyethylene.・Preblinz”, Volume 18 (
2) pp. 182-187 (1977)). That is, the polymer solution is passed through a small column packed with an inert packing material (“Chromosorb PJ”) to coat the polymer on the packing surface, and then the temperature of this column is continuously increased to obtain a less crystalline material. The eluate is eluted in descending order of the number of methyl branches, and the eluate is introduced into a differential refractometer, and a methyl branch distribution curve is calculated from the data from the differential refractometer and the column temperature (the number of methyl branches decreases as the column temperature increases). get.

Although this document states that a combination of the methyl branch distribution (crystalline distribution) and the molecular weight distribution is preferable, there is no specific description thereof.

On the other hand, a method that consists of filling a column with a porous packing material and passing a polymer solution through the column and eluting molecules in descending order of molecular size is called the GPC method and has been praised as a method for determining the molecular weight distribution of polymers. (Aldgelt et al. “Gel Permeation Chromatography”
(Published by Marcel Detzker, USA, 1971)).

If these two methods are combined, the correlation between the chemical or molecular structure of a polymer and its molecular weight distribution can be analyzed, but simply combining the two methods will not allow the analysis of polymers by molecular structure using, for example, a fractional dissolution column method. Separate,
As mentioned above, if the molecular weight distribution is then determined for each classification by the GPC method, there is a problem in terms of analysis speed.

The present inventors have developed a method for solving the above points and performing binary fractionation of molecular composition fractionation and molecular size fractionation in a short time.
One method has already been proposed in Japanese Patent Publication No. Sho 62-7975. In this method, when performing compositional fractionation using the fractional dissolution column method, the polymer to be analyzed is precipitated on the packing material in the column, and the precipitated polymer is eluted by raising the temperature in stages. The main operating step is to send the sample in batches to a molecular weight distribution analyzer. Furthermore, the above-mentioned publication introduces one example of an apparatus as a specific example of this method.

This device consists of a composition separation unit A that is equipped with a fractional dissolution column and a flow path change valve that performs stepwise fractional dissolution, a molecular size separation unit B that separates the polymer fractionated in unit A by molecular size, and a sample polymer separation unit B. It has a solvent supply unit C that supplies solvent for fractional dissolution and polymer solution transfer to units A and B, and a detection unit D that detects the fractionation results obtained in unit A. is connected to an automatic temperature controller and valve controller.

Although this device example is noteworthy as one of the effective embodiments of the above method, it is not necessarily fully satisfactory from a practical point of view. In other words, specifically, for example, to check the decrease in valve sealing performance due to the composition separation column and the flow path change valve, which are subject to large temperature changes, being in the same unit, the performance of the column, and the constant flow performance of the pump. For example, there is no mechanism for
There are concerns that there will be a decline in measurement accuracy during long-term continuous operation and problems with equipment maintenance.

[11) Summary of the invention The present invention improves the above-mentioned device example, and improves measurement accuracy.
The aim is to provide a polymer fractionation measurement device that can be operated continuously for a long period of time. 1) Establishment of an independent temperature control system according to the characteristics of each operating mechanism, 2) Confirmation of the performance of the column used and quantitative performance of the pump. The aim is to achieve this objective by installing an internal standard solution injection mechanism for the purpose of the test.

Therefore, the polymer fractionation measuring device according to the present invention includes a sample polymer solution injection port, a sample polymer solution metering loop, an internal standard solution injection mechanism including a liquid metering loop and a liquid injection valve, and a flow path having a system flow path change valve. Equipped with a change valve unit A and a column filled with a packing material,
A composition separation unit for fractionating the molecular composition of the sample polymer solution transferred from the sample polymer solution metering loop by precipitating the dissolved polymer onto the packing material and performing fractional dissolution by stepwise temperature elevation in the column. B, a molecular size separation unit C equipped with a column packed with a packing material, and for separating the sample polymer fraction solution, which is compositionally separated in unit B and transferred batchwise, by molecular size, and a sample port in unit B. , a solvent supply unit D for supplying a constant flow of solvent for fractional dissolution of remer and transfer of a produced sample polymer fraction solution, and a detection unit E for detecting the fractionation results obtained in unit C and measuring the molecular weight distribution. , a system controller,
It is equipped with an automatic temperature controller that is connected to each of the units ASB and C and independently controls the temperature at a temperature that ensures free flow of the polymer solution, and the system controller controls the temperature controller and the unit A This feature is characterized in that it is possible to control the valves inside the valve.

According to the polymer fractionation measuring device of the present invention, the flow path changing valve unit A and the molecular composition fractionation unit B are independent, and the temperature control is performed independently in each of the units A, B, and C. Improvements have been made in terms of maintenance, and the introduction of an internal standard solution injection mechanism has ensured measurement accuracy, overcoming the above-mentioned problems and improving binary fractionation and DI determination regarding molecular composition and molecular size. Inline and complete automation will be achieved at a practical level.

(III) Detailed Description of the Invention 1. Separation Measuring System FIG. 1 is a system diagram showing an example of a separation measuring device according to the present invention.

Unit A is a heating vessel or oven containing valves to alter the flow path of the system. The valve in the oven is controlled at a constant temperature to allow free flow of the polymer solution, through which the test polymer solution or fractionated polymer solution passes.

Valve switching is performed by system controller Ab. The system controller performs central control of the entire device.

Unit B is a composition separation unit that utilizes the temperature dependence of the solubility of the test polymer in a solvent, and is also housed in a heating container, that is, an oven. This separation is performed by increasing the temperature of the precipitated polymer in stages, and since it is necessary to lower the temperature for the next separation, unit B is equipped with an automatic temperature controller Ba. The automatic temperature controller has temperature rise and fall synchronized by system controller Ab.

Unit C is a molecular size separation unit that separates compositionally separated polymers by molecular size. This too,
It is housed in a heating container or oven.

Unit D is a unit that supplies a constant flow of solvent for fractional dissolution of the test polymer and transportation of the polymer solution in Unit B.

Unit E is a detection unit that detects the classification results obtained by unit C. The flow cell of the detector is controlled at a constant temperature to allow free flow of the polymer solution. The detection results are recorded by a recorder or data processing device.

The ovens of units A, B and C are set at a temperature that ensures free flow of the polymer solution, but are characterized by independent temperature control due to the specificity and operability of each function. Automatic temperature controller Aa
, Ba, and Ca are connected to each other. Units A and B are guaranteed to have free flow of polymer even at the same temperature, but unit B is a unit that constantly undergoes repeated temperature changes, so installing a valve inside an oven that experiences such temperature changes will Temperature changes can cause valve seals to deteriorate, making long-term continuous operation difficult. Also,
Oven C, which performs fractionation based on molecular size, must be kept at a constant temperature at all times in order to maintain the life of the fractionation column and the accuracy of molecular size measurement, so an oven (unit B) that changes temperature should not be placed adjacent to it. Uni-Soto A and C are controlled at a constant temperature, but considering the ease of replacing the filter (r) in Uni-Soto A and repairing valves, etc., it is difficult to change the temperature rapidly. It must be independent of C.

Although the basic flow path is shown in FIG. 1, it may be slightly modified depending on the type of detector, etc.

The equipment in units A to E is as follows.

Symbol Content a: Solvent tank b, Buripump C: Filter d; Pump head (metering pump) e:
Deaeration pipe f: Three-way valve g: Injection valve h:
Sample loop i: Sample injection section j: Sample loop (quantification loop) k:
Fractionation column (crystalline) 1: Preheating loop m: Internal standard injection valve n: Internal standard solution tank 0: Internal standard solution injection valve p: Three-way valve q: Internal standard-standard solution quantitative loop r:
Filter s, s: GPC column t: Detector U: Internal standard solution outlet valve V:
The valves in the waste liquid tank 2 and the separation operation unit A are set to valve position -1, and the sample polymer solution is injected through the injection port i using a syringe or the like. The solution is filled from the injection port i through the valve boat 2.3 into the loop j. Excess solution is discharged at 8 through valve boat 6.7.

After the polymer solution is filled in the loop, the valve position is automatically changed to -2, 3, 4, 1 according to instructions from the system controller unit Ab, and all or part of the solution in the loop is transferred to the composition separation column k. be introduced. The solution is transferred into the column by extrusion with the solvent supplied from unit D through piping 17. 3.4. Move through 9.

After a certain amount of solution introduced into column k has moved, the valve position becomes -4 (the amount of solution introduced is determined by the flow rate of the metering pump and the set time of valve position -3. However, the maximum amount is determined by the metering loop j ).

Thereafter, the solution moves until it is set in the center of the column, and stops at valve position -1.

(This timing depends on the metering pump flow rate and piping 4 to 9.
The internal volume between the columns is set by the volume within the column. ) Unit B is then cooled to a temperature sufficient to cause most of the dissolved polymer in the solution in the column to precipitate out and form a thin film on the surface of the packing material in the column. Although the solvent in the column heat-shrinks due to cooling, the solvent always remains in unit D.
from both sides of the column via bypass piping 15, 16 to compensate for thermal shrinkage. If the thermal shrinkage of the solvent is not compensated for during cooling, gas entrainment will occur in the column (
(or occurrence), there are parts where the solvent does not flow during polymer elution, which deteriorates the accuracy of separation, and if the mixed gas is sent to a column that separates by molecular size, the accuracy of molecular size separation also decreases. It also causes noise in the detector.

After cooling to a predetermined temperature and elapsed for a certain period of time, the pulp position automatically moves to -4, and the solution containing only the unprecipitated polymer in the column is transferred to a fixed volume of solvent (from unit D to the pipe 17°) at a rate that does not disturb the inside of the column. 15.16.5.4.9)
The entire amount is transferred to unit C via piping 10, 11, 12, 21, 20, 25. The valve then automatically returns to valve position -1.

The polymer transferred to unit C in this case is a polymer that is soluble at the temperature of unit B. This polymer is subjected to molecular size separation in column S of unit C, and a detector t (differential refractometer, infrared spectrophotometer, etc.) detects the concentration of the polymer in the solution and its special chemical structure (e.g. carbonyl group, methyl group). etc. are detected.

While fractionation is being performed in unit C, unit B is heated to a certain temperature, and compositional fractionation is performed at that temperature. After a certain period of time that does not interfere with the separation of the polymer solution previously introduced into unit C, the valve position is automatically changed to -4.
The entire solution containing the newly eluted polymer segment at the above temperature is transferred to unit C with a constant volume of solvent. In unit C, separate measurements similar to those described above are performed.

Valve m and loop q in unit A are the mechanism for injecting the internal standard into unit C. The purpose of injecting the internal standard substance is to (1) confirm the constant flow rate of the pump, and (2) confirm the performance of the column.

As the internal standard substance, it is generally possible to use a low molecular weight substance that is soluble in a solvent at room temperature, can be detected by the detector t, has no molecular weight distribution, and does not interfere with fractional measurement. The internal standard substance is also added to the test polymer solution injected from injection port i. Since the internal standard substance is soluble at the initial elution temperature, transferring the soluble polymer in the column to unit C consumes the entire amount of internal standard substance from column K. From the second elution, the internal standard is no longer present and the polymer-only solution is in Unit C.
will be transferred to.

Therefore, after the entire amount of the polymer solution passes through valve m after the second elution operation, valve m automatically becomes the valve position -5, and the solution containing the internal standard in loop q is transferred to unit C. be done.

After a certain amount has been transferred, it automatically returns to valve position -1.

Then, to introduce the internal standard solution into loop q,
Valve U is opened and the solution is introduced by N2 pressure applied to tank n. Once the time required to displace the entire quantity in loop q has elapsed, valve U is closed and the operation is terminated.

This operation is automatically repeated from the second elution on the column. A valve p attached to the tank ° is used for pressurizing the tank and releasing pressure. The pressure inside the tank is controlled by a constant pressure valve. Valve O is a valve attached to an inlet for filling tank n with the internal standard solution. Note that the first replacement of the internal standard substance in loop q is performed in the above operation after the first elution on the column.

Thereafter, in the same manner, the temperature of unit B is raised stepwise to the pre-programmed temperature, and each time the solution containing the newly eluted polymer fraction is transferred to unit C in a quarter manner and fractionated into molecular sizes. , a two-dimensional fractionation with respect to composition-molecular weight is performed.

3. Specific example of fractional measurement The main points of a specific example of fractional measurement using the apparatus of the present invention are as follows. It goes without saying that these specific conditions can be changed as appropriate.

(1) The separation column has a length of 5-20cm and an inner diameter of 1.0-0. The normal size is about 2 cm. Stainless steel is suitable.

The filler is suitably an inert material such as "Celite" or glass beads having a particle size of about 50 to 400 mesh (Tyler). A sintered film with a pore size of about 5 to 10 μm or a filter with a pore size of 400 mesh (Tyler) was installed at the inlet and outlet joints of the column.
Preferably, a stainless steel filter is provided.

In order to maximize the effect of the present invention, the space volume within the column after filling with the packing material must be 0. It is recommended that the volume be about 5 to 2 ml.

(2) The concentration of the injection sample solution is about 2 to 20 mg/ml. 110ll1
Approximately /m1 is appropriate.

The injection volume is about 0.5 to 2 ml (1 to 4 ml by polymer weight).
0mg) is normal.

(3) Quantification loop j The internal volume is usually about 0.2 to 2 ml. Around 1m1 is appropriate.

(4) Cooling rate of unit B 1-b /hour) is normal. Approximately 2°C/min is appropriate.

In general, the cooling rate is not constant; it is better to cool faster at higher temperatures and slower at lower temperatures.

(5) Extrusion rate of solution in fractionation column n 0.5-2ml
/ minute is normal. Approximately 1 ml/min is appropriate.

(6) Extrusion volume of solution in fractionation column n 0.5 to 3 ml
The degree is normal. Around 1m1 is appropriate.

Note that this extrusion volume should be selected from the viewpoint of extruding the entire amount of the polymer eluted within the column.

(7) Fractionation column n temperature increase rate 0.5~b Around a minute is appropriate.

(8) Piping materials Stainless steel is suitable.

(9) Unit C The column S has a length of about 30 to 90 cm, an inner diameter of about 4 to 8 cm, and is suitably filled with an inorganic material such as crosslinked polystyrene or porous silica. The number of columns does not necessarily have to be two, and is determined by the measurement range of molecular weight distribution, separation ability, etc.

(10) Detector There are differential refractometers, infrared spectrophotometers, viscometers, and others.

Also, two or more types of detectors may be used in combination.

For example, a differential refractometer or infrared spectrophotometer can be provided at the outlet of the column to measure the polymer concentration in the effluent solvent and plot the amount of effluent polymer versus time.

(11) Suitable materials include those whose refractive index changes with changes in solvent polymer concentration, those that have little absorption at the detection infrared wavelength, and others.

Specific examples include 0-dichlorobenzene, trichlorobenzene, BTX, carbon tetrachloride, and ethylene tetrachloride.

(12) Internal standard solution quantitative loop (q) internal volume 0.2
~2 ml is normal, and around 1 ml is appropriate.

(13) Internal standard solution tank (n) An internal volume of 300 to 500 ml is appropriate. In order to prevent pressurized N2 from entering the analysis channel, a liquid level detector is installed, and a mechanism is installed to stop the injection of the internal standard substance solution when the liquid level falls below the lower limit level. .

Specifically, the internal standard substance is, for example, 2.4-t-butyl-p-cresol, which is dissolved in a solvent such as O-dichlorobenzene.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a specific example of a separation measuring device according to the present invention, and FIG. 2 is a piping diagram showing valve positions of a flow path changing valve unit A. Unit A...flow path change valve unit, unit B
...Composition separation unit, Unit C...Molecular science separation unit, Unit D...Solvent supply unit, Unit E...Detection unit, Aa, Ba, Ca...
Automatic temperature controller, Ab...system controller, j...sample polymer fixed amount loop, k...column for composition fractionation, n...internal standard solution tank, q...
- Internal standard solution quantitative loop, SL, 82...GPC column. Applicant's agent - Yu Sato (bl Figure 2 (C) (d') Figure 2 Barufuiwa M5 (e) Second doctor

Claims (1)

[Claims] A flow path change valve unit A having a sample polymer solution injection port, a sample polymer solution metering loop, an internal standard liquid injection mechanism including a liquid metering loop and a liquid injection valve, and a system flow path change valve, and a column filled with a packing material. for separating the molecular composition of the sample polymer solution transferred from the sample polymer solution quantitative loop by precipitating the dissolved polymer onto the packing material and performing fractional dissolution by stepwise temperature elevation in the column. A composition separation unit B, a molecular size separation unit C equipped with a column filled with a packing material, and a molecular size separation unit C for separating the sample polymer fraction solution, which is compositionally separated in unit B and transferred batchwise, by molecular size; a solvent supply unit D for supplying a constant flow of solvent for the fractional dissolution of the sample polymer and transport of the produced sample polymer fraction solution; and a detection unit E for detecting the fractionation results obtained in the unit C and measuring the molecular weight distribution. , a system controller, and an automatic temperature controller that is connected to each of the units A, B, and C and independently controls the temperature to ensure free flow of the polymer solution, and the system controller A polymer fractionation measuring device for automatically performing binary fractionation and measurement of polymer composition and molecular size in-line, characterized in that it is capable of controlling a temperature controller and controlling a valve in the unit A. .